Final answer:
The organizer induces the formation of dorsal mesoderm by inhibiting BMP signaling. This process is part of organogenesis in vertebrate development where cell differentiation and axis formation are regulated by specific growth factors and signaling molecules.
Step-by-step explanation:
The organizer induces the formation of the dorsal mesoderm by inhibiting BMP signaling. During the process of organogenesis, which occurs after gastrulation in vertebrate development, specific signaling pathways are critical. The dorsal mesoderm, which includes structures such as the notochord and eventual spinal cord, develops due to the inhibition of BMP (Bone Morphogenetic Protein) signaling. This inhibition allows for the establishment of the dorsal structures. BMPs are part of a broader family of growth factors, and their inhibition is essential for the proper differentiation of cells in the ectoderm. If BMP signaling is not inhibited, cells will not properly differentiate into neural tissue, leading to defects in the formation of the neural system and the dorsal body axis.
An experiment by Spemann and Mangold highlighted the importance of the dorsal cells in notochord development. When dorsal cells were transplanted to a different location on an embryo, they still formed a notochord. This demonstrated the intrinsic programming of these cells to signal the formation of dorsal structures, emphasizing the importance of specific growth factors and signaling pathways during the early stages of embryonic development.